Deployment tool &amp; methodology for running and setting frac plugs and releasing frac balls

ABSTRACT

The disclosure relates to a method for deploying a frac ball within a subterranean location, having the steps of: deploying a wireline tool into the subterranean location, wherein the wireline tool defines a cavity housing the frac ball; pumping a fluid into the subterranean location; retaining the frac ball in the cavity while the fluid is pumped below a predetermined flow rate; setting a frac plug into the subterranean location; and firing one or more guns into the subterranean location.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable.

BACKGROUND

Technical Field: The disclosure relates to the field of plug andperforate processes in the petrochemical industry, in particular,devices and methods relating to the release or delivery of a frac ballor other occluding object onto a seat of a frac plug, after setting thefrac plug into place.

In conventionally known plug and perforate systems, a bottom holeassembly (also referred to herein as “BHA”) may include one or moreperforating guns, a plug setting tool, and a frac plug or isolationdevice. Some BHAs may optionally further include a ball release tool.The BHA delivers and sets a frac plug or isolation device at a desiredlocation within the casing. The frac plug or isolation device typicallyhas a throughbore which may be blocked or plugged with a frac ball orother object. A first known conventional means of delivering the fracball include setting the frac plug, then firing the guns to perforatethe well, and then dropping the frac ball through the casing anddelivering the frac ball to the ball seat on the frac plug. This methodof conveying the ball requires valuable time, fuel and fluid, whichresults in a relatively large environmental footprint. A second knownconventional means of delivering the frac ball includes simultaneouslycarrying the frac ball and frac plug to the desired location, which is acomparatively smaller environmental footprint compared to the firstknown conventional means but is problematic when the perforating gunshave misfired and the frac ball has nonetheless been inserted into theseat of the frac plug. In this scenario, the seating of the frac ball inthe frac plug prevents the wireline from easily or efficiently runningreplacement guns. Effective or desired pumping is inhibited with thefrac ball set into the seat of the frac plug if the guns are misfiring.To resume normal oilfield operations, a handful of processes may be usedto unseat the frac ball or object from the frac plug seat and redeliverthe BHA to the desired position. All of these corrective measures aregenerally expensive in terms of cost, operational delay and/or neededequipment and resources. US Patent Publication No. 20150252643, which isherein incorporated by reference in its entirety, proposes a device andmethod of automatic release of the frac ball upon the successful firingof at least one perforating gun, wherein the pressure released from thefired gun causes the release of the frac ball. However, the devices andmethods under US20150252643 do not allow for precise operator control ofwhen the frac ball is released. By way of example, the firing of any onegun may generate sufficient pressure for the frac ball to automaticallyrelease and engage the frac plug. In essence the frac ball may beautomatically released regardless of whether the gun(s) fire correctlyor misfire. The firing of less than all of the perforating guns may notbe sufficient to proceed with additional fracturing activities, despitethe automatic release of the frac ball. Thus, it may still be necessaryto run replacement guns into the casing, but because the frac ballautomatically seated onto the frac plug, this presents the same orsimilar problems as identified before. Additionally, the technologyinvolved in perforating the casing is continually changing, includingcharge shaping, penetration depth and amount of explosive charge. Whenthe amount of explosive charge is reduced but the penetration depth isthe unchanged, these conventional methods may result in increased riskof failure of rupturing the fluid pathways. Hence mitigation would berequired, and downhole mitigation takes up valuable rig time. Thus, aneed exists for an improved device and method for a running tool andcontrolled frac ball release.

BRIEF SUMMARY

The disclosure relates to a method for deploying a frac ball within asubterranean location, having the steps of: deploying a wireline toolinto the subterranean location, wherein the wireline tool defines acavity housing the frac ball; pumping a fluid into the subterraneanlocation; retaining the frac ball in the cavity while the fluid ispumped below a predetermined flow rate; setting a frac plug into thesubterranean location; and firing one or more guns into the subterraneanlocation.

As used herein, the terms “frac” or “frack” also includes encompassesthe terms “fracture”, “fracturing”, “fracking”, “fracing”, or fraccingor “hydraulic fracturing” as commonly understood in the petrochemicalfield.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary embodiments may be better understood, and numerousobjects, features, and advantages made apparent to those skilled in theart by referencing the accompanying drawings. These drawings are used toillustrate only exemplary embodiments and are not to be consideredlimiting of its scope, for the disclosure may admit to other equallyeffective exemplary embodiments. The figures are not necessarily toscale and certain features and certain views of the figures may be shownexaggerated in scale or in schematic in the interest of clarity andconciseness.

FIG. 1 depicts a side view of an exemplary embodiment of a deploymentwireline tool for running and setting a frac plug, wherein an outersleeve of the tool is partially cut away or removed in the depiction.

FIG. 2 depicts a cross-section view of the exemplary embodiment of thedeployment wireline tool of FIG. 1.

FIG. 3 depicts a cross-section view of an exemplary embodiment of adeployment wireline tool, without depiction of an outer sleeve, andwherein the frac plug is disengaged from the outer sleeve and an innermandrel.

FIG. 4 depicts a cross-section view of an exemplary embodiment of thedeployment wireline tool along line 4-4 in FIG. 3.

FIG. 5 depicts a side view of an exemplary embodiment of the deploymentwireline tool and bottom hole assembly, wherein the frac plug has beenset into the casing.

FIG. 5A depicts an enlarged cross-section side view of the exemplaryembodiment of the deployment wireline tool in FIG. 5.

FIG. 6 depicts a side view of an exemplary embodiment of the deploymentwireline tool and bottom hole assembly wherein the guns have fired andperforated the casing and the wellbore.

FIG. 6A depicts an enlarged cross-section side view of the exemplaryembodiment of the deployment wireline tool in FIG. 6, wherein the fracball is retained within the wireline tool during and after thesuccessful firing of the guns.

FIG. 7 depicts a side view of an exemplary embodiment of the deploymentwireline tool and bottom hole assembly wherein the pump is pumping anincreased fluid flow rate above a predetermined flow rate, thusreleasing the frac ball from the deployment wireline tool.

FIG. 7A depicts an enlarged cross-section side view of the exemplaryembodiment of the deployment wireline tool in FIG. 7.

FIG. 8 depicts a side view of an exemplary embodiment of the releasedfrac ball as set or engaged with the frac plug, wherein the exemplaryembodiment of the deployment wireline tool and bottom hole assembly havebeen removed from the perforated casing and wellbore.

FIG. 9 depicts a side view of an exemplary embodiment of the releasedfrac ball as set or engaged with the frac plug and isolating the zoneuphole of the frac plug, wherein the pump is pumping fluid into theisolated zone and fracturing the perforations.

FIG. 10 depicts a cross-section view of an exemplary embodiment of thedeployment wireline tool, wherein the frac ball is retained by one ormore springs.

FIG. 11 depicts a cross-section view of an exemplary embodiment of thedeployment wireline tool, wherein the frac ball is released from the oneor more springs of FIG. 10.

DESCRIPTION OF EMBODIMENT(S)

The description that follows includes exemplary apparatus, methods,techniques, and instruction sequences that embody techniques of theinventive subject matter. However, it is understood that the describedembodiments may be practiced without these specific details.

FIG. 1 depicts a side view of an exemplary embodiment of a deploymentwireline tool 10 for running and setting a frac plug 50, wherein anouter sleeve 13 of the running tool 10 is partially cut away to betterdepict the inner mandrel 20 within. FIG. 10 depicts a side cross-sectionview of an alternative exemplary embodiment of the tool 10, wherein thetool 10 has delivered or set the frac plug 50, and before release of thefrac ball 30. The running and/or setting tool 10 may define an upholeend 11 and a downhole end 12. The uphole end 11 of the running tool 10may further include an adjuster sub, a supporting member, coupler orother connector 15 which may support the inner mandrel 20 (see e.g.FIGS. 10s and 11) or, in alternative exemplary embodiments, connect therunning tool 10 to other tools or parts of a bottom hole assembly(hereinafter, also referred to as “BHA”) 60. The adjuster sub 15 mayensure a proper fit and alignment of the components of BHA 60. A fracplug 50 may be connected or engaged at a downhole end 12 of the runningtool 10.

The running tool 10 includes an outer sleeve 13 and an inner mandrel 20.In FIG. 1, part of the outer sleeve 13 is cut away or removed to betterdepict the interior of running tool 10. The outer sleeve 13 may defineone or more outer sleeve flow or fluid ports, holes or openings 14. Byway of example only, the outer sleeve 13 may have or define two or fourports 14; any number of ports 14 are considered within the scope of thedisclosure. The inner mandrel 20 is located within the outer sleeve 13.The inner mandrel 20 may also define a first end 21 and a second end 22.The first end 21 of the inner mandrel 20 may be a substantiallycylindrical body or portion 23, having a smaller outer diameter 23 athan the interior/inner diameter 13 a of that of the outer sleeve 13.The second end of the inner mandrel 20 may be a substantially tubular orcylindrical body or portion 25, wherein body 25 has a larger outerdiameter 25 a than the inner mandrel cylindrical body 23 and which maycomplementarily fit within the outer sleeve 13. The first cylindricalbody 23 and second cylindrical body 25 may be connected together via afrustoconical, angled or sloped shoulder 24 between the two bodies 23and 25.

Referring at least to FIGS. 2-3, the inner mandrel 20 may further definea cavity or ball cavity 27 within the interior of the inner mandrel 20.The cavity 27 may be open at the second end 22 and extend at leastpartially into the first portion or body 23 of the inner mandrel 20. Oneor more inner mandrel fluid or flow ports, holes, or openings 26 may bedefined on the first portion 23 of the inner mandrel 20, wherein eachport or opening 26 is connected to the cavity 27. The openings 26 may beangled ports or openings, wherein the opening 26 is defined through theinner mandrel 20 at an angle 26 a to the longitudinal axis of therunning tool 10, and connects to cavity 27 at an angle 26 a which isconducive to the movement of fluid 81 into the cavity 27 as pumped bypump 80. By way of example, and not to be limited to such, there may bethree openings 26 distanced equally around the circumference or outerdiameter 23 a of the first body portion 23 of the inner mandrel 20. Thecavity 27 may have a larger or wider end 29 of the cavity 27, as locatedtowards the second end 22 or the downhole end 12.

In a first orientation or position 10 a (see e.g. FIG. 10), the cavity27 may house a ball, frack ball, frac ball, object or occluding object30 (see further, e.g. FIGS. 1, 2, 5A, and 6A). The wireline tool 10occupies the first position 10 a any time prior to the release of thefrac ball 30. The cavity 27 may also partially house the first end 51 ofthe frac plug or isolation device 50. The frac plug 50 further defines asecond end 52. A throughbore or through passage 57 is defined throughthe length of the frac plug 50. The throughbore 57 opens into a seat orball seat 54 at the first end 51 of the frac plug 50. The ball seat 54is complementary to the outer surface of the ball or occluding object30, such that when the ball 30 is seated, plugged or engaged against theseat 54 and the frac plug 50 is set into the casing, no flow can occurthrough the passage 57. The frac plug 50 may also have a circumferentialshoulder or extension 53 which may complementarily fit within the outersleeve 13 when the running tool 10 is assembled.

The inner mandrel 20 and frac plug 50 may each define a series of shearpin openings 31 and 55, respectively. Shear pin openings 31 may bedefined towards the second or downhole end 22 of the inner mandrel 20,in the widened portion 29 of the cavity 27. The shear pin openings 31may allow for the fixture of the frac plug 50 and compression of thecomponents of BHA 60 through the use or activation of shear pins orshear screws 56. Shear pin openings 55 may be defined towards the firstor uphole end 51 and on the outer surface of the frac plug 50. Shearpins 56 may be inserted into shear pin openings 31 and shear pinopenings 55 when same are aligned. The shear pins 56 may retain orsecure the frac plug 50 into place within the cavity 27 while the BHA 60is in the process of delivering the frac plug 50 to the desiredlocation. The shear pins 56 are configured to break or shear whensufficient predetermined or preset force is applied to the inner mandrel20 and outer sleeve 13.

The inner mandrel 20 further includes a number or a set of retentiondevices, springs or levers 40. As depicted in the figures, the springs40 are attached to the exterior surface of the inner mandrel 20 on thefrustoconical shoulder 24 and inserted into the cavity 27 through aspring opening 42 as defined on said shoulder 24. The springs 40 may beattached at a first end to the inner mandrel 20 via a fastener 41. Thespring opening 42 should be large enough or wide enough to allow, by wayof example only, at least a 20° angle deflection or flexibility of theflat spring 40 within the cavity 27. In an exemplary embodiment theremay be three openings 26 and three springs 40 with the three openings 26respectively generally aligned to direct flow pressure to the threesprings 40. In further alternative exemplary embodiments, the spring 40may instead be attached (via fasteners 41 or other means as known in theart) to the interior surface of the cavity 27, while allowing for thesame or similar amount of angle of deflection in the spring 40. Otherdesired angles of deflection, thickness, material, length and strengthin the spring 40 may be selected as desired by the operator of thesystem. An exemplary embodiment of the springs 40 and shear pin openings31 as located on the inner mandrel 20 is depicted in FIG. 4.

When assembled with the frack plug, frac plug, mandrel plug, orisolation device 50 for running said frac plug 50 to the desiredlocation or destination, the free end or unattached end of the springsor retention devices 40 may be located or situated in between the ball30 and the ball seat 54. The free or unattached end of the springs 40may optionally feature a means of retention such as a tab, hook, curveor lip 43 which further supports, retains or cages the ball 30 beforethe ball 30 is released via a preset flow rate 81 from the pump 80. Asdepicted in at least FIG. 2, a portion of the springs 40 and/or thespring tabs/hooks 43 may prevent the ball 30 from seating or engagingfully with the seat 54 such that there is a gap 32 allowing fluid toflow around the sides of the ball 30 and through the seat 54 and thethroughbore 57 of the frac plug 50. The profile of the spring 40 mayoptionally include further irregularities such as additional curves,curls, crimps/kinks/angles or other geometry to facilitate fluid flowthrough the gap 32 while retaining and supporting the ball 30 within thecage formed by the springs 40. In further exemplary embodiments, thespring 40 may retain the ball 30 without the hook 43 or any otherprofile irregularities. The fluid 81 may be pumped or motivated via thepump 80 both before and after the frac plug 50 is set into the casing61.

In a first position 10 a of the deployment wireline tool 10, wherein thesprings 40 are containing, retaining or securing the ball 30, (by way ofexample, as depicted in at least FIGS. 1 and 10), the ball 30 is fullyhoused within the cavity 27 of the inner mandrel 20. The ball 30, asdescribed above, may be in contact with or supported the springs 40 onan underside of the ball 30. The top of ball 30 may be in contact withor supported by an interior shoulder or extension 28 extended from theinterior wall of the cavity 27. The frac plug 50 may or may not bewithin the deployment wireline tool 10 in the first position 10 a (as itmay have already been set into the casing 61). In a second position 10 bof the deployment wireline tool 10, (by way of example, as depicted inat least FIGS. 7A and 11) wherein the springs 40 have released the ball30, the ball 30 is free to move with any pumped fluid flow 81 and may nolonger be in contact with the interior shoulder 28, the springs 40 andthe spring hooks 43.

Once the deployment wireline tool 10 is at the desired location withinthe wellbore 63 (or other subterranean environment or location 63) forthe frac plug 50, the tool 10 of BHA 60, carrying the ball or occludingobject 30 within the cavity 27, is manipulated and powered through thewireline 62 to apply a sufficient pulling force on the inner mandrel 20and/or a sufficient pushing force on the outer sleeve 13. As a result,the shear pins 56 are broken or sheared, and the frac plug 50 separatesfrom the inner mandrel 20 and sets or engages into the casing 61 (orother subterranean environment) at the desired location. Subsequently,the FIGS. 5-9 depict the process of flow actuated release or releasingof the frac ball 30 after the setting of the frac plug 50. In FIGS. 5and 5A, the frac plug or isolation device 50 of the bottom hole assembly60 has been set via the wireline 62 into the casing 61 within thewellbore 63. Further, the bottom hole assembly or BHA 60 has beenpulled, retracted or relocated uphole via wireline 62 to the desired orselected position within the wellbore 63 for the one or more guns 70 toperforate. In FIGS. 5 and 5A, the ball 30 is retained in the cavity 27and supported or retained by the springs 40 and the interior shoulder 28of the cavity 27. In FIGS. 6 and 6A, the operator has fired or poweredthe guns 70 via wireline 62 to puncture the casing 61 and wellbore 63with perforations 71. The ball 30 is still retained within the cavity 27by the springs 40 in FIGS. 2, 6 and 6A. In FIGS. 7 and 7A, the operatormay now set, via pump 80, an increased fluid flow rate, as shown byarrows 81, to flow around the guns 70 and other portions of the bottomhole assembly 60 to the running tool 10. The flow of the fluid 81 maytravel through the outer sleeve ports 14 to the inner mandrel ports 26and into the ball cavity 27 and towards the springs 40. Each of thesprings 40 have sufficient strength, thickness or stiffness to resist aflow rate 81 below the predetermined range or amount. As a result, theset of springs 40 retains the ball or object 30 within the cavity 27when the flow of the fluid 81 from the pump 80 is below such apredetermined or preset rate (as shown in FIGS. 1-3, and 5-6A). By wayof example only, the springs 40 may resist release of the ball 30 whenthe flow rate 81 is less than 5 gallons per minute. In an exemplaryembodiment, when the flow rate 81 is between 5 to 10 gallons per minuteor between 5 to 10 barrels per minute, or greater, the flow 81 may havesufficient force, pressure or strength to push or force the ball 30against and deflect the springs 40 away from the bottom of the ball 30.The fluid pressure required to release the ball 30 (i.e. overcome thesprings 40) is adjustable or dependent relative to the spring force. Asthe unattached ends of the springs 40 angle towards the interior of thecavity 27 during deflection, the ball 30 is released (as depicted inFIGS. 7A and 11). The operator thus can command the release of the ball30 as desired by adjusting the flow rate 81 above or below the presetflow rate accordingly.

The fluid 81, as delivered by pump 80, continues to flow through cavity27 to the throughbore 57 of the frac plug or isolation device 50. Theball 30, after release from the springs 40, travels with the fluid 81 toland, set or engage on or with the ball seat 54 on the frac plug 50, asseen in FIG. 8. As depicted in FIG. 9, once the ball 30 is seated on theseat 54, fluid flow is blocked/prevented through the passage 57, andadditional fluid may be pumped via pump 80 to create one or morefractures 64 through the one or more perforations 71 in the wellbore 63,thus inducing or stimulating production in said wellbore 63. In essencethe pump controller/operator has flexibility in determining when (i.e.the timing) and commanding release of the ball 30.

If one or more of the guns 70 misfire, or in the case of any othermalfunction, or under any circumstance as desired by the operator of thesystem, so long as the fluid 81 has not been pumped to the wireline tool10 at or above the predetermined flow rate, the BHA 60 having retainedthe frac ball 30 may be retrieved and a replacement redeployed to thedesired location within the wellbore 63. Unlike the prior art or otherconventionally known devices and methods, with the exemplary embodimentsdescribed herein, the operator may control or command the timing of therelease of the frac ball 30 by directing, controlling or manipulatingthe flow of fluid 81 from the pump 80, preventing the ball 30 frominadvertently, accidentally, or prematurely releasing and blocking theflow of fluid into wellbore 63 and past the frac plug 50. Without a ball30 blocking pressure or fluid flow in the wellbore 63/casing 61, the BHA60 may be easily retrieved and redeployed using commonly known,inexpensive mitigation techniques and with relatively minor setback tothe overall operation.

While the embodiments are described with reference to variousimplementations and exploitations, it will be understood that theseembodiments are illustrative and that the scope of the inventive subjectmatter is not limited to them. Many variations, modifications,additions, and improvements are possible. By way of example only,although the deployment wireline tool 10 and BHA 60 are frequentlydepicted and described herein as within a casing 61 and or wellbore 64,it is to be appreciated that same or similar exemplary embodiments ofthe devices and processes disclosed within may be applied to anysubterranean location or environment.

Plural instances may be provided for components, operations orstructures described herein as a single instance. In general, structuresand functionality presented as separate components in the exemplaryconfigurations may be implemented as a combined structure or component.Similarly, structures and functionality presented as a single componentmay be implemented as separate components. These and other variations,modifications, additions, and improvements may fall within the scope ofthe inventive subject matter.

1. A method for deploying a frac ball within a subterranean location,comprising the steps of: deploying a wireline tool into the subterraneanlocation, wherein the wireline tool defines a cavity housing the fracball; pumping a fluid into the subterranean location; retaining the fracball in the cavity while the fluid is pumped below a predetermined flowrate; setting a frac plug into the subterranean location; and firing oneor more guns into the subterranean location.
 2. The method according toclaim 1, further comprising the step of releasing the frac ball from thecavity when the fluid is pumped above the predetermined flow rate. 3.The method according to claim 2, wherein the step of retaining the fracball in the cavity is performed by one or more retention devicesretaining the ball within the cavity.
 4. The method according to claim3, wherein the predetermined flow rate is five gallons per minute. 5.The method according to claim 4, further comprising the step ofdeflecting an end of each of the one or more retention devices away froman underside of the ball in the cavity before the step of releasing thefrac ball from the cavity.
 6. The method according to claim 5, furthercomprising the step of preventing the frac ball from release after thefiring fewer than all of the one or more guns.
 7. The method accordingto claim 6, further comprising the step of retrieving the wireline tooland the frac ball from the subterranean location.
 8. The methodaccording to claim 6, further comprising the step of seating the fracball into a seat of the frac plug.
 9. The method according to claim 8,wherein the wireline tool comprises at least an outer sleeve and aninner mandrel, and wherein the cavity is located within the innermandrel.
 10. The method according to claim 9, wherein the step ofsetting the frac plug into the subterranean location further comprisesthe steps of applying a pushing force to the outer sleeve; applying apulling force to the inner mandrel; and shearing one or more shear pinsconnected to the frac plug.
 11. The method according to claim 10,wherein the step of firing one or more guns into the subterraneanlocation comprises the step of creating one or more perforations in thesubterranean location.
 12. The method according to claim 11, furthercomprising the steps of preventing fluid flow through the frac plug;forcing fluid through the one or more perforations; and creatingfractures in the subterranean location.
 13. A wireline deployment toolfor release of a frac ball comprising: a cavity defined within thewireline deployment tool; wherein the frac ball is housed within thecavity; and a retention device attached at a first end to a wall of thecavity, and wherein a second end of the retention device is unattachedand releasably engaged with the frac ball.
 14. The wireline deploymenttool according to claim 13, wherein the retention device is configuredto resist deflection if a fluid flow rate is below five gallons perminute.
 15. The wireline deployment tool according to claim 14, furthercomprising an outer sleeve housing an inner mandrel; and wherein thecavity is located within the inner mandrel.
 16. The wireline deploymenttool according to claim 15, further comprising a first fluid portdefined on the outer sleeve; and a second fluid port defined on theinner mandrel.
 17. The wireline deployment tool according to claim 16,wherein the second fluid port is defined at an angle through the innermandrel.
 18. The wireline deployment tool according to claim 17, whereinthe retention device is flexible to an angle of deflection of 20°. 19.The wireline deployment tool according to claim 18, further comprising afrac plug connected to the inner mandrel.
 20. The wireline deploymenttool according to claim 19, wherein the retention device comprises atleast three retention devices.
 21. A method for controlled release of afrac ball within a subterranean environment, comprising the steps of:running a wireline tool downhole into the subterranean environment,wherein the frac ball is housed within the wireline tool; pumping afluid downhole at a current flow rate; preventing the release of thefrac ball from the wireline tool when the current flow rate is below apreselected flow rate; increasing the current flow rate to thepreselected flow rate and then releasing the frac ball from the wirelinetool; and seating the frac ball into a frac plug set within thesubterranean location.